The research being conducted in this laboratory focuses on the embryonic development of organ systems. Differentiation in vivo and in vitro is being analyzed in developing salivary glands, lungs, pancreas, nervous system, and smooth muscle. The involvement of extracellular macromolecules, including collagen and proteoglycans, in organ morphogenesis is being analyzed by correlating effects of inhibition of specific synthesis with effects on morphogenetic behavior of the experimental system. The roles of intracellular microfilaments and microtubules in morphogenic movements are being correlated with actin and tubulin quantities and distribution during such movements. These studies are utilizing antibodies against tubulin and actin for quantitative radioimmunoassays and for indirect immunofluorescence. In addition, we are using the antibodies to assess antigenic similarities and differences between tubulins and actins from different species and different tissues.